Toe iron for safety ski bindings

ABSTRACT

1,141,595. Toe-iron for safety ski-bindings. H. MARKER. 24 May, 1966 [4 June, 1965], No. 23180/66. Heading A6D. A toe-iron for safety ski bindings with a damping arrangement for lateral jolts, comprises a base part 1 mounted rigidly on a ski, a sole retainer 7 which has flanges 13 and 14, which engage on the projection 2 of part 1, being guided and held in the groove 3 of the projection 2 by pin members 9 and 10 on which are mounted rollers 11 and 12. The sole retainer 7 is capable of describing a circular path having a radius 6 i.e. the radius of the groove 3, and under certain conditions, it is possible for the rollers 11 or 12 to move into the curve branches 4 or 5 causing the sole-retainer 7 to perform a forwardly directed tipping movement which ensure the release of the foot. Another embodiment is described in which additionally projections on the sole retainer are braced against a guide path of the base part and during the tipping movement the projections on the sole retainer slide over the corners of the guide path, making it possible for the corners to move into the gap between the projections on the sole retainer.

Sept. 26, 1967 H. MARKER 3,343,845

TOE IRON FOR SAFETY SKI BINDINGS Filed June 1, 1966 2 Sheets-Sheet 1 lNVENTOR Hcmnes Marker ymfimmgm ATTORNEYS P H. MARKER TOE IRON FOR SAFETY SKI BINDINGS Filed June 1, 1966 2 Sheets-Sheet 3 Fig.4

I lllllll'" .5 I g A INVENTOR Honnes Marker ATTORNEYS United States Patent 3,343,845 TOE IRON FOR SAFETY SKI BINDINGS Hannes Marker, Hauptstrasse 51-53, Garmisch- Partenkirchen, Germany Filed June 1, 1966, Ser. No. 554,548 Claims priority, application Germany, June 4, 1965,

1 Claim. (Cl. 28011.35)

The object of the present invention is to provide a toeiron for safety ski bindings, which is adapted first to absorb the forces arising transversely of the longitudinal direction of the ski through a long damping travel and only to release the foot after more prolonged application of such forces or under very marked torsion forces which could result in an injury to the skier. In order to achieve a substantially simplified construction, it is intended to utilise the tightening force exerted by the heel in the direction of the ski tip in such a way that no particular spring or returning element is required on the toe-iron.

Various embodiments of toe-irons for safety ski bindings are known which resiliently absorb lateral forces through a prolonged travel. It is however of disadvantage here that in the known toe-irons, either really complicated spring or return elements have to be provided in order to apply corresponding force to counteract the forces arising transversely of the longitudinal direction of the ski, the difiicult diversion of the spring forces additionally requin'ng very much stronger springs than would be possible if the spring were to work directly on the return curve or the like.

According to the invention, a particular spring-action return element for the toe-iron is rendered unnecessary, the force of the tightening action applied by the heel in the direction of the ski tip being utilised to generate the resistance of the toe-iron to being released. According to the invention, this is achieved in that the sole-retaining member which engages over the front edge of the boot sole is, on both sides of its normal position, guided as far as the release position on a circular curve of a base part mounted rigid on the ski, the middle point of the said base part being situated between the toe-iron and the heel portion, the lateral branches of the guide curve being directed forwardly, the sole-retainer being braced against the guide curve by means of two rollers or the like which are disposed symmetrically of the longitudinal centre line. Since the radius of the pivoting movement of the sole-retaining member is smaller than the radius of the natural pivoting movement of the boot, the centre point of which is in the region of the heel, the boot, when released or even during relatively small pivoting movements which are not intended to release the foot, is guided slightly backw-ardly against the action of the tightening force. The effect of this is to increase the tightening force, which tends to force the toe-iron, through the boot, back into its starting position, so that a self-centring of the toeiron or its sole-retaining member results. Only when the lateral force arising is so great that one of the bracing parts of the sole-retaining member extends to the lateral branch of the curve which is adjacent to it, is the foot quickly released without there being any area in which return of the toe-iron and boot to the middle position could be hindered by the tightening force acting from the rear, as is the case with known toe-irons with automatic return. Also when the boot is placed in the binding the sole-retainer is automatically centred in the middle position as soon as the tightening force is applied to it through the boot, though this is true only on condition that one of the bracing parts of the sole-retainer is not already guided into a lateral branch of the curve. In this position, however, fitting of the binding would not be possible in any case.

3,343,845 Patented Sept. 26, 1967 Two possible embodiments of the invention are illustrated in the ensuing description, which makes reference to the appended drawings, in which:

FIG. 1 is a vertical cross-section through afirst embodiment of a toe-iron according to the invention;

FIG. 2 is a plan view of the toe-iron shown in FIG. 1;

FIG. 3 is a plan view of the toe-iron shown in FIGS. 1 and 2, in the released position;

FIG. 4 is a vertical cross-section through a second embodiment, and

FIG. 5 is a plan view of FIG. 4.

FIGS. 1-3 show a toe-iron according to the invention. It consists of the base part 1 which is to be mounted rigidly on the ski, and the sole-retainer 7 which has flanges 13, 14, which engage on the projection 2 of the part 1, being guided and held in the groove 3 of the projection 2 by means of pin members 9, 10 on which are mounted rollers 11, 12. In the event of forces arising transversely of the longitudinal direction of the ski, the sole-retainer 7 describes a circular path having a radius 6, Le. the radius of the arcuate groove 3. Since the radius 6 is smaller than the radius 8 of the circular path described by the toe of the boot about a pivot point located for example at the height of the ankle, the sole-retainer 7, during such a pivoting movement, is guided somewhat rearwardly in the longitudinal direction of the ski. At the same time, however, also due to the differing radii 6 and 8 and the somewhat increasing tightening force, the sole-retainer 7 is guided back to its starting position at any time upon cessation of a transverse force acting on it but not as yet dangerous.

When a predetermined angular position of the foot is reached, it becomes possible for the rollers 11, 12 to move into the curve branches 4, 5 which are directed forwardly in the direction of the ski tip, the sole-retainer 7 performing a forwardly directed tipping movement which ensures release of the foot in a critical situation. The appropriate position is shown in FIG. 3.

FIGS. 4 and 5 show another embodiment of a toe-iron according to the invention. In this case, the base part which is to be mounted rigidly on the ski comprises the cover plates 2%, 21 and the interposed spacer and guide member 22. Both cover plates 20, 21 have grooves 24, 25 machined into them, the sole-retainer 23 being slidingly guided in the said grooves through pin members 26 and 27. Furthermore, the projections 28, 29 on the soleretainer 23, are additionally braced against the guide path 30 of the part 22. The method of opera-tion is the same as with the embodiment shown in FIGS. 1-3 because, in this case too, the sole-retainer 23 describes a circular movement corresponding to the radius of the guide grooves 24, 25 or of the guide path 30, this radius being again smaller than the radius of the circular path described by the toe of the boot during a pivoting movement about an assumed point situated for example at the height of the ankle.

The guide grooves 24, 25 similarly have forwardly pointing curve branches 33, 34 and 35, 36, directed towards the point of the ski, so that the sole-retainer 23 likewise has a possibility of moving forwardly after a predetermined pivoting angle has been reached, in order that the foot may be released. During this tilting movement, the guide projections 28, 29 slide over the corners 31 or 32 of the guide path 30 and it becomes possible for the corners 31, 32 to move into the gap 37 in the sole-retainer 23.

I claim:

A toe iron for safety ski bindings comprising a base means attached to a ski, said base means being formed with a guide surface extending transversely to the longitudinal direction of the ski on an arcuate path, the center of curvature of which is located on the longitudinal centerline of the ski behind the toe iron but in front of the center of rotation of a boot engaging the toe iron, the length of the guide surface corresponding approximately to the range of foot-twist occurring during harmless lateral jolts, and said guide surface terminating in guide faces which are inclined sharply forwardly to said transverse guide surface, a sole-retaining member, and a pair of support elements engaging said transverse guide surface and disposed symmetrically of the longitudinal centerline of the ski, said support elements being carried by said sole-retaining member and guiding the transverse movement thereof.

References Cited UNITED STATES PATENTS 3,079,164 2/1963 De Place 280-l1.35 3,224,786 12/1965 Tosalli 280l1.35

, BENJAMIN HERSH, Primary Examiner.

10 JAMES H. BRANNEN, Assistant Examiner. 

